Limit on the number of relations in a database

"Bob Badour" <bbadour_at_golden.net> wrote in message news:4fmdnbSTrq9wG9PdRVn-uA_at_golden.net...
> "Paul Vernon" <paul.vernon_at_ukk.ibmm.comm> wrote in message
> news:c27tbf$2mg0$1_at_gazette.almaden.ibm.com...
> > "Drago Ganic" <drago.ganic_at_in2.hr> wrote in message
> > news:c1r4ku$dku$1_at_sunce.iskon.hr...
> > [snip]
> > > I do agree that we can model relations so that all attributs are "not
> > null"
> > > and work with 2VL. That is one solution (i don't think it's a
practical
> > one,
> > > because we get far to many relations in our data model).
> >
> > In theory, what's the practical limit for the number of relations in a
> > database?

>

I think the question is, which theory(s) do we bring to bear.

Physics might tell us the theoretical limit to the quantity of information storable in a given volume of space. Then given an encoding scheme for relations we could find some upper limit.

Economics might have some insight into the number of different predicate types needed to describe the business of some highly complex company.

However, I would go for this:

    At the limit, lets say a database has exactly one tuple in every one of it's relations. Therefore the maximum number of relations in that database will simply be the number of tuples that can be encoded in the physical device chosen to store the database.

In short, the limit of the number of relations is approx the number of bytes encodable in the database.

A nice result for those who might like, say, a database full of random tuples.

Regards
Paul Vernon
Business Intelligence, IBM Global Services Received on Wed Mar 10 2004 - 14:31:44 CET